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Hybridhunter's avatar
Hybridhunter
Explorer
Oct 11, 2014

Thermostat upgrade - 2 stage w/ heat strip - fan speed issue

So I'm upgrading my new Coleman Mach 1 Air Conditioner with heat strip, to an external digital programmable multi stage thermostat. I find all aspects pretty straightforward. I am trying to devise a ...
Chris_Bryant's avatar
Chris_Bryant
Explorer II
Oct 12, 2014
The way Dometic does (did) it is bt using one fan relay to energize the fan, the other is an spdt relay, and toggles between low (unenergized) and high (energized). That's why simply hooking the high fan lead doesn't work for them.
You could just add relays to do that for the Coleman, except you would run the 12 volt control through them.

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